A method of implementing glyphs so that each block of glyphs can be independently read, by putting into the sync lines of each block data on how the included data is formatted and therefore, how it should be read out.
A glyph is a diagonal line printed on paper that slopes at one angle to indicate one state of a bit, and at a different angle to indicate the other state. Here, a block of information is in numerical or word form, and there is no intended image. Glyphs are small, typically {fraction (1/60)}th of an inch on center and a 10 by 10 glyph block appears as a gray square.
Numerous patents have issued on the generation and use of glyphs, such as U.S. Pat. No. 5,245,165, Self-Clocking Glyph Code for Encoding Dual Bit Digital Values Robustly; U.S. Pat. No. 5,449,895, Explicit Synchronization for Self-Clocking Glyph Codes; and U.S. Pat. No. 5,521,372, Framing Codes for Robust Synchronization and Addressing of Self-Clocking Glyph Codes, which are incorporated by reference herein.
Typically, glyphs are used in areas that appear to be gray, but are actually a number of blocks in series, with the first one or more containing all of the meta data required to read the remaining blocks in a xe2x80x9ckey-codewordxe2x80x9d. A result of this system is that the number of each block must be known before its data can be read meaningfully, and individual blocks can not exist independently.
It would be advantageous for each block to exist independently, so that individual blocks could be placed anywhere on the page.
A block of glyphs typically consists of four sync lines of glyphs framing a rectangular or square group of data glyphs. For a numerical example, the sync lines could be ten glyphs in length and at right angles to define a 10 by 10 glyph block enclosing an eight by eight glyph area to be used for data. In this implementation, the sync lines could use some of its sync bits to identify the block as a glyph block, and the remaining sync bits to identify the format of the glyphs in the enclosed eight by eight glyph area. The result is a readable data block that can be ⅙th of an inch which appears to be gray and which can be printed anywhere on the page.
Each unit is self-contained, and uniquely numbered if necessary. Units can be placed anywhere, and their meaning can be a function of their proximity to other graphical elements on the page. Units can also work together. Each small glyph can be thought of as a (labeled) unit. They can also be associated with other units, to form a larger (and more heavily error-correction protected) message. They also can be used to generate a very simple implementation for embedding digital data within logos, text, line graphics, presentation graphics, etc, and this can be done for either a small, single-unit message, or for a large message that uses many units.